About Devil and Devil

The demon Sword and the pure Ios are fighting their 101st battle during one of the many wars between pures and demons, when, both severely wounded, they fall on Earth, where each of them has to take the body of a human to survive; to their astonishment, the bodies they take are those of two twins, and, to make things worse, the angel has taken the body of the violent rebel Kanna, while the demon has taken that of the weak and defenseless Soma.